package com.gome.security.util;

import java.io.FileInputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.Cipher;

import com.sun.org.apache.xml.internal.security.utils.Base64;

import demo.RSASignature;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class RSAHelper {

	/**
	 * 得到公钥
	 * 
	 * @param key
	 *            密钥字符串（经过base64编码）
	 * @throws Exception
	 */
	public static PublicKey getPublicKey(String key) throws Exception {
		byte[] keyBytes;
		keyBytes = (new BASE64Decoder()).decodeBuffer(key);

		X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance("RSA");
		PublicKey publicKey = keyFactory.generatePublic(keySpec);
		return publicKey;
	}

	/**
	 * 得到私钥
	 * 
	 * @param key
	 *            密钥字符串（经过base64编码）
	 * @throws Exception
	 */
	public static PrivateKey getPrivateKey(String key) throws Exception {
		byte[] keyBytes;
		keyBytes = (new BASE64Decoder()).decodeBuffer(key);

		PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance("RSA");
		PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
		return privateKey;
	}

	/**
	 * 得到密钥字符串（经过base64编码）
	 * 
	 * @return
	 */
	public static String getKeyString(Key key) throws Exception {
		byte[] keyBytes = key.getEncoded();
		String s = (new BASE64Encoder()).encode(keyBytes);
		return s;
	}

	public static void main(String[] args) throws Exception {

		KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
		// 密钥位数
		keyPairGen.initialize(2048);
		// 密钥对
		KeyPair keyPair = keyPairGen.generateKeyPair();

		// 公钥
		PublicKey publicKey = (RSAPublicKey) keyPair.getPublic();

		// 私钥
		PrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

		String publicKeyString = getKeyString(publicKey);
	//	System.out.println("public:\n" + publicKeyString);

		String privateKeyString = getKeyString(privateKey);
//		System.out.println("private:\n" + privateKeyString);

		// 加解密类
		Cipher cipher = Cipher.getInstance("RSA");// Cipher.getInstance("RSA/ECB/PKCS1Padding");

		String str = "我们都很好！邮件：@sina.com";
		String str1 = "businessId=20130815112230315&mernum=898110248990216&oOrderNumber=002000108102&orderNumber=000004300002&tranDate=2013-08-15";
		
		// 明文
		byte[] plainText = str1.getBytes();

		
		 CertificateFactory of;
			String bv = null;
			PublicKey pk = null;
			try {
				of = CertificateFactory.getInstance("x.509");
				FileInputStream in = new FileInputStream("D:/key/gomerb.cer");
				X509Certificate Cert = (X509Certificate) of.generateCertificate(in);
				pk = Cert.getPublicKey();
				BASE64Encoder bse = new BASE64Encoder();
				bv = bse.encode(pk.getEncoded());
			} catch (Exception e) {
				e.printStackTrace();
			}
			System.out.println(bv);
		
		// 加密
		cipher.init(Cipher.ENCRYPT_MODE, pk);
		byte[] enBytes = cipher.doFinal(plainText);
		
		
		String dd=(new BASE64Encoder()).encodeBuffer(enBytes);
		String ss = new String(Base64.encode(enBytes));
		System.out.println(dd);
		System.out.println(ss);
		//System.out.println(RSASignature.doCheck(str1,ss, publicKeyString));
//		// 通过密钥字符串得到密钥
//		publicKey = getPublicKey(publicKeyString);
//		privateKey = getPrivateKey(privateKeyString);
//		// 解密
//		cipher.init(Cipher.DECRYPT_MODE, privateKey);
//		byte[] deBytes = cipher.doFinal(enBytes);
//
//		publicKeyString = getKeyString(publicKey);
//		System.out.println("public:\n" + publicKeyString);
//
//		privateKeyString = getKeyString(privateKey);
//		System.out.println("private:\n" + privateKeyString);
//
//		String s = new String(deBytes);
//		System.out.println(s);

	}

}
